1. Field of the Invention
The present invention relates to an endoscope apparatus preferable for inspection and an inspection method using an endoscope.
2. Description of the Related Art
Conventionally, endoscopes have been widely used for performing observation or various kinds of treatment on a subject to be examined by inserting an elongated endoscope into a body cavity, and the like. Also in industrial fields, industrial endoscopes, which are capable of observing and inspecting flaws, corrosion, and the like in a boiler, turbine, engine, chemical plant, etc., have been widely used.
An endoscope includes an elongated insertion portion and is capable of observing an object image, which is imported from the distal end portion of the insertion portion, at the proximal end side of the insertion portion. An image pickup device such as CCD is provided at the distal end portion of the insertion portion, or a camera is attached to an eye piece portion on the proximal end side of the insertion portion, to thereby convert the object image into a video signal and enable the video signal to be transmitted to a processor connected to the operator's hand side position of the endoscope. The processor generates an endoscopic image based on the transmitted video signal, and sends the endoscopic image to the monitor to cause the monitor to display the endoscopic image.
Incidentally, a rigid endoscope is sometimes used for determining whether an inspection object is non-defective or defective. The distance between the inspection object and the distal end portion of the insertion portion of the rigid endoscope is fixed by inserting the rigid endoscope from an inspection hole using a jig. This allows the inspection object to be displayed in a certain definite size all the time on the display screen of the monitor, which enables a flaw size or the like to be confirmed easily.
However, it is sometimes difficult to determine whether the inspection object is non-defective or defective by just looking at the endoscopic image displayed on the display screen of the monitor. For example, when the non-defective or defective determination is made based on whether the size of the flaw is larger than a threshold, there is a case where the size of the flaw is close to the threshold. In such a case, it is not easy to determine whether the inspection object is non-defective or defective by just looking at the endoscopic image displayed on the display screen, and it is sometimes necessary to measure the dimension of the flaw.
In view of the above-described circumstances, Japanese Patent Application Laid-Open Publication No. 2009-199089 proposes an endoscope apparatus capable of performing stereoscopic measurement for measuring the dimension of such a flaw. If the endoscope apparatus disclosed in Japanese Patent Application Laid-Open Publication No. 2009-199089 is employed, it is possible to accurately measure the dimension of the flaw and the like and surely determine whether the inspection object is non-defective or defective.